This invention relates to a semiconductor package, and more particularly to a semiconductor package having an improved shape of a metallized portion of the cover for sealing the semiconductor element mounted on a ceramic substrate.
An air-tightly sealed semiconductor package for use in computers usually includes a cover consisting of a material of a high thermal conductivity brazed or soldered to a ceramic substrate, on which a semiconductor element, such as an LSI circuit chip is mounted. Such air-tightly sealed semiconductor packages include, for example, a semiconductor package disclosed in Japanese Patent Laid-Open No. 276237/1986.
The sealing of a semiconductor element on a ceramic substrate is done by soldering in advance a joint portion of a metallized ceramic substrate and that of a cover, or by placing a solder foil or a wire rod on a joint portion of a ceramic substrate, aligning the ceramic substrate and cover with each other, and heating the resultant ceramic substrate and cover so as to melt the solder.
According to a conventional method of producing a semiconductor package of this kind, only the opposed joint surfaces of the joint portions of the ceramic substrate and cover are generally subjected to a metallization treatment.